Construction of Concentrating Photovoltaic (P/V) Systems with conventional parabolic reflectors or with parabolic total reflection reflectors is a well known technology. Yet, current concentrating P/V systems in the market are not cheaper than the conventional, and generally expensive, flat P/V systems. The reason for such market condition is that the construction of parabolic Total Reflection Reflectors (TRRs) from common transparent glass, which would be the cheapest and the most resilient solution, often faces construction difficulties which prevent accomplishing large concentrating ratios.
The main of such difficulties is that the parabolic TRRs from glass have, due to their construction and related technical aspects, rear rectangular prisms with larger height and width than the ones made out of acrylic (compare, for example, the 2-10 mm sizes of those TRRs made of glass with the 0.02-0.2 mm of the acrylic ones). In addition, rectangular prisms present diffusion and poor focusing of the solar rays, which typically gets worse exponentially as their height and their width increase, and thus limits drastically the concentration ratios.
Moreover, such optical imperfection limits the use of secondary reflectors employed for the reduction of the solar image size and the achievement of a Narrow Secondary Beam and high level of concentration ratios, which would be necessary for supplying solar radiation to hollow Solar Wave Guides (Solar Arteries) for the injection of such solar radiation into buildings in order to employ it for solar lighting. The same optical imperfection also limits the construction of hollow Solar Wave Guides (Solar Arteries) with small losses for the transfer of the Solar Radiation inside the buildings for the replacement of artificial lightning with solar lighting.
Until today there have been efforts to transfer solar radiation inside buildings by using large diameter fiber optics. Such approach, even for the most clear fiber optic materials, presents great losses for the solar spectrum (e.g., 50% losses for propagation distance of 20-30 meter).